| 1 |
/* |
| 2 |
* dircache.c |
| 3 |
* Copyright (C) 2002 Florin Malita <mali@go.ro> |
| 4 |
* |
| 5 |
* This file is part of LUFS, a free userspace filesystem implementation. |
| 6 |
* See http://lufs.sourceforge.net/ for updates. |
| 7 |
* |
| 8 |
* LUFS is free software; you can redistribute it and/or modify |
| 9 |
* it under the terms of the GNU General Public License as published by |
| 10 |
* the Free Software Foundation; either version 2 of the License, or |
| 11 |
* (at your option) any later version. |
| 12 |
* |
| 13 |
* LUFS is distributed in the hope that it will be useful, |
| 14 |
* but WITHOUT ANY WARRANTY; without even the implied warranty of |
| 15 |
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the |
| 16 |
* GNU General Public License for more details. |
| 17 |
* |
| 18 |
* You should have received a copy of the GNU General Public License |
| 19 |
* along with this program; if not, write to the Free Software |
| 20 |
* Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA |
| 21 |
*/ |
| 22 |
|
| 23 |
#include <unistd.h> |
| 24 |
#include <stdlib.h> |
| 25 |
#include <string.h> |
| 26 |
#include <pthread.h> |
| 27 |
|
| 28 |
#include <sys/stat.h> |
| 29 |
|
| 30 |
#include <lufs/proto.h> |
| 31 |
#include <lufs/fs.h> |
| 32 |
|
| 33 |
#include "list.h" |
| 34 |
#include "dircache.h" |
| 35 |
|
| 36 |
static char root_dir[]="/"; |
| 37 |
static char current_dir[]="."; |
| 38 |
|
| 39 |
static unsigned long |
| 40 |
hash(char *name){ |
| 41 |
unsigned long res = 0; |
| 42 |
unsigned int i; |
| 43 |
|
| 44 |
for(i = 0; i < strlen(name); i++) |
| 45 |
if(name[i] != '/') |
| 46 |
res = 0x21413 * (res + name[i]); |
| 47 |
|
| 48 |
return res % NBUCKETS; |
| 49 |
} |
| 50 |
|
| 51 |
static void |
| 52 |
delete_dir(struct directory *d){ |
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struct list_head *p, *tmp; |
| 54 |
struct direntry *de; |
| 55 |
|
| 56 |
TRACE("in"); |
| 57 |
list_for_each_safe(p, tmp, &d->d_entries){ |
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de = list_entry(p, struct direntry, e_list); |
| 59 |
list_del(&de->e_list); |
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free(de->e_name); |
| 61 |
if(de->e_link) |
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free(de->e_link); |
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free(de); |
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} |
| 65 |
|
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list_del(&d->d_list); |
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free(d->d_name); |
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free(d); |
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|
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TRACE("out"); |
| 71 |
} |
| 72 |
|
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struct dir_cache* |
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lu_cache_create(struct list_head *cfg){ |
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struct dir_cache *cache; |
| 76 |
int i; |
| 77 |
const char *c; |
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|
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TRACE("creating dir cache..."); |
| 80 |
|
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if(!(cache = malloc(sizeof(struct dir_cache)))) |
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return NULL; |
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|
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memset(cache, 0, sizeof(struct dir_cache)); |
| 85 |
|
| 86 |
for(i = 0; i < NBUCKETS; i++) |
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INIT_LIST_HEAD(&cache->buckets[i]); |
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|
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pthread_mutex_init(&cache->lock, NULL); |
| 90 |
|
| 91 |
cache->ttl = DEF_TTL; |
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if((c = lu_opt_getchar(cfg, "LUFSD", "DirCacheTTL")) && atoi(c)) |
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cache->ttl = atoi(c); |
| 94 |
if((c = lu_opt_getchar(cfg, "MOUNT", "dir_cache_ttl")) && atoi(c)) |
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cache->ttl = atoi(c); |
| 96 |
|
| 97 |
cache->entries = DEF_NENTRIES; |
| 98 |
if((c = lu_opt_getchar(cfg, "LUFSD", "DirCacheEntries")) && atoi(c)) |
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cache->entries = atoi(c); |
| 100 |
if((c = lu_opt_getchar(cfg, "MOUNT", "dir_cache_entries")) && atoi(c)) |
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cache->entries = atoi(c); |
| 102 |
|
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TRACE("entries: %d, ttl: %d", cache->entries, cache->ttl); |
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|
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return cache; |
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} |
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|
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void |
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lu_cache_destroy(struct dir_cache *cache){ |
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struct list_head *p, *tmp; |
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int i; |
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|
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for(i = 0; i < NBUCKETS; i++){ |
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list_for_each_safe(p, tmp, &cache->buckets[i]){ |
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delete_dir(list_entry(p, struct directory, d_list)); |
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} |
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} |
| 118 |
|
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free(cache); |
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} |
| 121 |
|
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static struct directory* |
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search(struct dir_cache *cache, char *dir){ |
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struct list_head *p, *tmp; |
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struct directory *d; |
| 126 |
int hsh; |
| 127 |
|
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hsh = hash(dir); |
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|
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TRACE("search %s in bucket %u, size=%u", dir, hsh, cache->lengths[hsh]); |
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|
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list_for_each_safe(p, tmp, &cache->buckets[hsh]){ |
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d = list_entry(p, struct directory, d_list); |
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|
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if(time(NULL) - d->d_stamp >= (unsigned long) cache->ttl){ |
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TRACE("%s expired...", d->d_name); |
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delete_dir(d); |
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cache->lengths[hsh]--; |
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TRACE("directory deleted"); |
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}else if(!strcmp(dir, d->d_name)){ |
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TRACE("%s found", dir); |
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d->d_stamp = time(NULL); |
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return d; |
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} |
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} |
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|
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TRACE("dir not found"); |
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return NULL; |
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} |
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|
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int |
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lu_cache_lookup(struct dir_cache *cache, char *dir, char *file, struct lufs_fattr *fattr, char *link, int buflen){ |
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struct directory *d; |
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struct direntry *de; |
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struct list_head *p; |
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int res = -1; |
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|
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TRACE("looking up %s in dir %s", file, dir); |
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|
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pthread_mutex_lock(&cache->lock); |
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|
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if(!(d = search(cache, dir))) |
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goto out; |
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|
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list_for_each(p, &d->d_entries){ |
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de = list_entry(p, struct direntry, e_list); |
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if(!strcmp(file, de->e_name)){ |
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TRACE("file found"); |
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|
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memcpy(fattr, &de->e_attr, sizeof(struct lufs_fattr)); |
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if(link){ |
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if(de->e_link){ |
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if(snprintf(link, buflen, "%s", de->e_link) >= buflen){ |
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WARN("link too long!"); |
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link[buflen - 1] =0; |
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} |
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}else{ |
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link[0] = 0; |
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} |
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} |
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|
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res = 0; |
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goto out; |
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} |
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} |
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|
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TRACE("file not found!"); |
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|
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out: |
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pthread_mutex_unlock(&cache->lock); |
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return res; |
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} |
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|
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static void |
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shrink(struct dir_cache *cache, int hsh){ |
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struct directory *dir; |
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|
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TRACE("shrinking bucket %u, len=%u", hsh, cache->lengths[hsh]); |
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|
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if(list_empty(&cache->buckets[hsh])) |
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return; |
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|
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dir = list_entry(cache->buckets[hsh].prev, struct directory, d_list); |
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|
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TRACE("deleting dir %s", dir->d_name); |
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|
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delete_dir(dir); |
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cache->lengths[hsh]--; |
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} |
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|
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static void |
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check_dir(struct directory *d){ |
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struct list_head *p, *tmp; |
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struct direntry *e; |
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struct lufs_fattr dummy; |
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int dot = 0, dotdot = 0; |
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|
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memset(&dummy, 0, sizeof(struct lufs_fattr)); |
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dummy.f_nlink = 1; |
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dummy.f_uid = dummy.f_gid = 1; |
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dummy.f_mode = S_IFDIR | S_IRWXU | S_IRGRP | S_IXGRP; |
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dummy.f_mtime = dummy.f_atime = dummy.f_ctime = time(NULL); |
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dummy.f_size = 512; |
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|
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do{ |
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list_for_each_safe(p, tmp, &d->d_entries){ |
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e = list_entry(p, struct direntry, e_list); |
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|
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if(!strcmp(e->e_name, ".")){ |
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TRACE("'.' entry found"); |
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list_del(&e->e_list); |
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list_add(&e->e_list, &d->d_entries); |
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dot = 1; |
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continue; |
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} |
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|
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if(!strcmp(e->e_name, "..")){ |
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TRACE("'..' entry found"); |
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list_del(&e->e_list); |
| 240 |
if(!dot) |
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list_add(&e->e_list, &d->d_entries); |
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else |
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list_add(&e->e_list, d->d_entries.next); |
| 244 |
|
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dotdot = 1; |
| 246 |
} |
| 247 |
} |
| 248 |
|
| 249 |
if(!dot) |
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lu_cache_add2dir(d, ".", NULL, &dummy); |
| 251 |
|
| 252 |
if(!dotdot) |
| 253 |
lu_cache_add2dir(d, "..", NULL, &dummy); |
| 254 |
|
| 255 |
}while((!dot) || (!dotdot)); |
| 256 |
|
| 257 |
} |
| 258 |
|
| 259 |
void |
| 260 |
lu_cache_add_dir(struct dir_cache *cache, struct directory *d){ |
| 261 |
struct directory *dir; |
| 262 |
int hsh; |
| 263 |
|
| 264 |
hsh = hash(d->d_name); |
| 265 |
|
| 266 |
TRACE("adding dir %s to bucket %i", d->d_name, hsh); |
| 267 |
|
| 268 |
check_dir(d); |
| 269 |
|
| 270 |
pthread_mutex_lock(&cache->lock); |
| 271 |
|
| 272 |
if((dir = search(cache, d->d_name))){ |
| 273 |
TRACE("directory already in cache, deleting..."); |
| 274 |
delete_dir(dir); |
| 275 |
cache->lengths[hsh]--; |
| 276 |
} |
| 277 |
|
| 278 |
d->d_stamp = time(NULL); |
| 279 |
|
| 280 |
list_add(&d->d_list, &cache->buckets[hsh]); |
| 281 |
cache->lengths[hsh]++; |
| 282 |
|
| 283 |
while(cache->lengths[hsh] > cache->entries) |
| 284 |
shrink(cache, hsh); |
| 285 |
|
| 286 |
pthread_mutex_unlock(&cache->lock); |
| 287 |
|
| 288 |
TRACE("out"); |
| 289 |
} |
| 290 |
|
| 291 |
int lu_cache_readdir(struct dir_cache *cache, char *dir, |
| 292 |
fuse_dirh_t h, fuse_dirfil_t filler) |
| 293 |
{ |
| 294 |
struct directory *d; |
| 295 |
struct direntry *de; |
| 296 |
struct list_head *p; |
| 297 |
int res = -1; |
| 298 |
|
| 299 |
TRACE("reading directory %s", dir); |
| 300 |
|
| 301 |
pthread_mutex_lock(&cache->lock); |
| 302 |
|
| 303 |
if(!(d = search(cache, dir))) |
| 304 |
goto out; |
| 305 |
|
| 306 |
list_for_each(p, &d->d_entries){ |
| 307 |
de = list_entry(p, struct direntry, e_list); |
| 308 |
filler(h, de->e_name, 0); |
| 309 |
} |
| 310 |
|
| 311 |
d->d_stamp = time(NULL); |
| 312 |
|
| 313 |
res = 0; |
| 314 |
|
| 315 |
out: |
| 316 |
pthread_mutex_unlock(&cache->lock); |
| 317 |
TRACE("out"); |
| 318 |
return res; |
| 319 |
} |
| 320 |
|
| 321 |
int |
| 322 |
lu_cache_lookup_file(struct dir_cache *cache, char *file, struct lufs_fattr *fattr, char *link, int buflen){ |
| 323 |
int res; |
| 324 |
|
| 325 |
char *sep, *dir; |
| 326 |
|
| 327 |
if(!(sep = strrchr(file, '/'))){ |
| 328 |
WARN("separator not present!"); |
| 329 |
return -1; |
| 330 |
} |
| 331 |
|
| 332 |
*sep = 0; |
| 333 |
|
| 334 |
if(sep == file) |
| 335 |
dir = root_dir; |
| 336 |
else |
| 337 |
dir = file; |
| 338 |
|
| 339 |
if(*(sep+1)) |
| 340 |
file = sep + 1; |
| 341 |
else |
| 342 |
file = current_dir; |
| 343 |
|
| 344 |
TRACE("dir: %s, file: %s", dir, file); |
| 345 |
|
| 346 |
res = lu_cache_lookup(cache, dir, file, fattr, link, buflen); |
| 347 |
*sep = '/'; |
| 348 |
|
| 349 |
return res; |
| 350 |
} |
| 351 |
|
| 352 |
int |
| 353 |
lu_cache_invalidate(struct dir_cache *cache, char *file){ |
| 354 |
struct directory *d; |
| 355 |
char *sep, *dir; |
| 356 |
|
| 357 |
if(!(sep = strrchr(file, '/'))){ |
| 358 |
WARN("separator not present!"); |
| 359 |
return -1; |
| 360 |
} |
| 361 |
|
| 362 |
*sep = 0; |
| 363 |
|
| 364 |
if(sep == file) |
| 365 |
dir = root_dir; |
| 366 |
else |
| 367 |
dir = file; |
| 368 |
|
| 369 |
TRACE("invalidating dir %s", dir); |
| 370 |
|
| 371 |
pthread_mutex_lock(&cache->lock); |
| 372 |
|
| 373 |
if(!(d = search(cache, dir))){ |
| 374 |
*sep = '/'; |
| 375 |
pthread_mutex_unlock(&cache->lock); |
| 376 |
return -1; |
| 377 |
} |
| 378 |
|
| 379 |
d->d_stamp = 0; |
| 380 |
|
| 381 |
pthread_mutex_unlock(&cache->lock); |
| 382 |
*sep = '/'; |
| 383 |
|
| 384 |
return 0; |
| 385 |
} |
| 386 |
|
| 387 |
struct directory* |
| 388 |
lu_cache_mkdir(char *dir){ |
| 389 |
struct directory *res; |
| 390 |
|
| 391 |
TRACE("create dir %s", dir); |
| 392 |
|
| 393 |
if(!(res = malloc(sizeof(struct directory)))){ |
| 394 |
WARN("out of mem!"); |
| 395 |
return NULL; |
| 396 |
} |
| 397 |
|
| 398 |
memset(res, 0, sizeof(struct directory)); |
| 399 |
|
| 400 |
if(!(res->d_name = malloc(strlen(dir) + 1))){ |
| 401 |
WARN("out of mem!"); |
| 402 |
free(res); |
| 403 |
return NULL; |
| 404 |
} |
| 405 |
|
| 406 |
INIT_LIST_HEAD(&res->d_entries); |
| 407 |
res->d_stamp = time(NULL); |
| 408 |
strcpy(res->d_name, dir); |
| 409 |
|
| 410 |
return res; |
| 411 |
} |
| 412 |
|
| 413 |
int |
| 414 |
lu_cache_add2dir(struct directory *d, char *fname, char *link, struct lufs_fattr *fattr){ |
| 415 |
struct direntry *de; |
| 416 |
|
| 417 |
TRACE("adding %s->%s to %s", fname, link, d->d_name); |
| 418 |
|
| 419 |
if(!(de = malloc(sizeof(struct direntry)))) |
| 420 |
goto fail; |
| 421 |
|
| 422 |
|
| 423 |
if(!(de->e_name = malloc(strlen(fname) + 1))) |
| 424 |
goto fail_de; |
| 425 |
|
| 426 |
|
| 427 |
if(link) |
| 428 |
de->e_link = malloc(strlen(link) + 1); |
| 429 |
else |
| 430 |
de->e_link = malloc(2); |
| 431 |
|
| 432 |
if(!de->e_link) |
| 433 |
goto fail_ename; |
| 434 |
|
| 435 |
memcpy(&de->e_attr, fattr, sizeof(struct lufs_fattr)); |
| 436 |
strcpy(de->e_name, fname); |
| 437 |
if(link) |
| 438 |
strcpy(de->e_link, link); |
| 439 |
else |
| 440 |
strcpy(de->e_link, ""); |
| 441 |
|
| 442 |
list_add_tail(&de->e_list, &d->d_entries); |
| 443 |
|
| 444 |
return 0; |
| 445 |
|
| 446 |
fail_ename: |
| 447 |
free(de->e_name); |
| 448 |
fail_de: |
| 449 |
free(de); |
| 450 |
fail: |
| 451 |
WARN("out of mem!"); |
| 452 |
return -1; |
| 453 |
} |
| 454 |
|
| 455 |
void |
| 456 |
lu_cache_killdir(struct directory *d){ |
| 457 |
struct list_head *p, *tmp; |
| 458 |
struct direntry *de; |
| 459 |
|
| 460 |
TRACE("in"); |
| 461 |
|
| 462 |
list_for_each_safe(p, tmp, &d->d_entries){ |
| 463 |
de = list_entry(p, struct direntry, e_list); |
| 464 |
list_del(&de->e_list); |
| 465 |
free(de->e_name); |
| 466 |
if(de->e_link) |
| 467 |
free(de->e_link); |
| 468 |
free(de); |
| 469 |
} |
| 470 |
|
| 471 |
free(d->d_name); |
| 472 |
free(d); |
| 473 |
|
| 474 |
} |
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